diff options
| -rw-r--r-- | block/as-iosched.c | 139 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 86 | ||||
| -rw-r--r-- | block/deadline-iosched.c | 128 | ||||
| -rw-r--r-- | block/elevator.c | 147 | ||||
| -rw-r--r-- | block/ll_rw_blk.c | 2 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 17 | ||||
| -rw-r--r-- | include/linux/elevator.h | 2 |
7 files changed, 146 insertions, 375 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c index ad1cc40..6db4943 100644 --- a/block/as-iosched.c +++ b/block/as-iosched.c @@ -14,7 +14,6 @@ #include <linux/slab.h> #include <linux/init.h> #include <linux/compiler.h> -#include <linux/hash.h> #include <linux/rbtree.h> #include <linux/interrupt.h> @@ -95,7 +94,6 @@ struct as_data { struct as_rq *next_arq[2]; /* next in sort order */ sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */ - struct hlist_head *hash; /* request hash */ unsigned long exit_prob; /* probability a task will exit while being waited on */ @@ -162,11 +160,6 @@ struct as_rq { struct io_context *io_context; /* The submitting task */ /* - * request hash, key is the ending offset (for back merge lookup) - */ - struct hlist_node hash; - - /* * expire fifo */ struct list_head fifo; @@ -273,77 +266,6 @@ static void as_put_io_context(struct as_rq *arq) } /* - * the back merge hash support functions - */ -static const int as_hash_shift = 6; -#define AS_HASH_BLOCK(sec) ((sec) >> 3) -#define AS_HASH_FN(sec) (hash_long(AS_HASH_BLOCK((sec)), as_hash_shift)) -#define AS_HASH_ENTRIES (1 << as_hash_shift) -#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) - -static inline void __as_del_arq_hash(struct as_rq *arq) -{ - hlist_del_init(&arq->hash); -} - -static inline void as_del_arq_hash(struct as_rq *arq) -{ - if (!hlist_unhashed(&arq->hash)) - __as_del_arq_hash(arq); -} - -static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq) -{ - struct request *rq = arq->request; - - BUG_ON(!hlist_unhashed(&arq->hash)); - - hlist_add_head(&arq->hash, &ad->hash[AS_HASH_FN(rq_hash_key(rq))]); -} - -/* - * move hot entry to front of chain - */ -static inline void as_hot_arq_hash(struct as_data *ad, struct as_rq *arq) -{ - struct request *rq = arq->request; - struct hlist_head *head = &ad->hash[AS_HASH_FN(rq_hash_key(rq))]; - - if (hlist_unhashed(&arq->hash)) { - WARN_ON(1); - return; - } - - if (&arq->hash != head->first) { - hlist_del(&arq->hash); - hlist_add_head(&arq->hash, head); - } -} - -static struct request *as_find_arq_hash(struct as_data *ad, sector_t offset) -{ - struct hlist_head *hash_list = &ad->hash[AS_HASH_FN(offset)]; - struct hlist_node *entry, *next; - struct as_rq *arq; - - hlist_for_each_entry_safe(arq, entry, next, hash_list, hash) { - struct request *__rq = arq->request; - - BUG_ON(hlist_unhashed(&arq->hash)); - - if (!rq_mergeable(__rq)) { - as_del_arq_hash(arq); - continue; - } - - if (rq_hash_key(__rq) == offset) - return __rq; - } - - return NULL; -} - -/* * rb tree support functions */ #define rb_entry_arq(node) rb_entry((node), struct as_rq, rb_node) @@ -1060,7 +982,6 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq) ad->next_arq[data_dir] = as_find_next_arq(ad, arq); list_del_init(&arq->fifo); - as_del_arq_hash(arq); as_del_arq_rb(ad, arq); } @@ -1349,8 +1270,6 @@ static void as_add_request(request_queue_t *q, struct request *rq) } as_add_arq_rb(ad, arq); - if (rq_mergeable(arq->request)) - as_add_arq_hash(ad, arq); /* * set expire time (only used for reads) and add to fifo list @@ -1428,42 +1347,17 @@ as_merge(request_queue_t *q, struct request **req, struct bio *bio) struct as_data *ad = q->elevator->elevator_data; sector_t rb_key = bio->bi_sector + bio_sectors(bio); struct request *__rq; - int ret; - - /* - * see if the merge hash can satisfy a back merge - */ - __rq = as_find_arq_hash(ad, bio->bi_sector); - if (__rq) { - BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector); - - if (elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_BACK_MERGE; - goto out; - } - } /* * check for front merge */ __rq = as_find_arq_rb(ad, rb_key, bio_data_dir(bio)); - if (__rq) { - BUG_ON(rb_key != rq_rb_key(__rq)); - - if (elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_FRONT_MERGE; - goto out; - } + if (__rq && elv_rq_merge_ok(__rq, bio)) { + *req = __rq; + return ELEVATOR_FRONT_MERGE; } return ELEVATOR_NO_MERGE; -out: - if (ret) { - if (rq_mergeable(__rq)) - as_hot_arq_hash(ad, RQ_DATA(__rq)); - } - *req = __rq; - return ret; } static void as_merged_request(request_queue_t *q, struct request *req) @@ -1472,12 +1366,6 @@ static void as_merged_request(request_queue_t *q, struct request *req) struct as_rq *arq = RQ_DATA(req); /* - * hash always needs to be repositioned, key is end sector - */ - as_del_arq_hash(arq); - as_add_arq_hash(ad, arq); - - /* * if the merge was a front merge, we need to reposition request */ if (rq_rb_key(req) != arq->rb_key) { @@ -1501,13 +1389,6 @@ static void as_merged_requests(request_queue_t *q, struct request *req, BUG_ON(!arq); BUG_ON(!anext); - /* - * reposition arq (this is the merged request) in hash, and in rbtree - * in case of a front merge - */ - as_del_arq_hash(arq); - as_add_arq_hash(ad, arq); - if (rq_rb_key(req) != arq->rb_key) { as_del_arq_rb(ad, arq); as_add_arq_rb(ad, arq); @@ -1591,7 +1472,6 @@ static int as_set_request(request_queue_t *q, struct request *rq, arq->request = rq; arq->state = AS_RQ_PRESCHED; arq->io_context = NULL; - INIT_HLIST_NODE(&arq->hash); INIT_LIST_HEAD(&arq->fifo); rq->elevator_private = arq; return 0; @@ -1628,7 +1508,6 @@ static void as_exit_queue(elevator_t *e) mempool_destroy(ad->arq_pool); put_io_context(ad->io_context); - kfree(ad->hash); kfree(ad); } @@ -1639,7 +1518,6 @@ static void as_exit_queue(elevator_t *e) static void *as_init_queue(request_queue_t *q, elevator_t *e) { struct as_data *ad; - int i; if (!arq_pool) return NULL; @@ -1651,17 +1529,9 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e) ad->q = q; /* Identify what queue the data belongs to */ - ad->hash = kmalloc_node(sizeof(struct hlist_head)*AS_HASH_ENTRIES, - GFP_KERNEL, q->node); - if (!ad->hash) { - kfree(ad); - return NULL; - } - ad->arq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, arq_pool, q->node); if (!ad->arq_pool) { - kfree(ad->hash); kfree(ad); return NULL; } @@ -1672,9 +1542,6 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e) init_timer(&ad->antic_timer); INIT_WORK(&ad->antic_work, as_work_handler, q); - for (i = 0; i < AS_HASH_ENTRIES; i++) - INIT_HLIST_HEAD(&ad->hash[i]); - INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]); INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]); ad->sort_list[REQ_SYNC] = RB_ROOT; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 3a3aee0..1b803c0 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -41,16 +41,6 @@ static DEFINE_SPINLOCK(cfq_exit_lock); #define CFQ_QHASH_ENTRIES (1 << CFQ_QHASH_SHIFT) #define list_entry_qhash(entry) hlist_entry((entry), struct cfq_queue, cfq_hash) -/* - * for the hash of crq inside the cfqq - */ -#define CFQ_MHASH_SHIFT 6 -#define CFQ_MHASH_BLOCK(sec) ((sec) >> 3) -#define CFQ_MHASH_ENTRIES (1 << CFQ_MHASH_SHIFT) -#define CFQ_MHASH_FN(sec) hash_long(CFQ_MHASH_BLOCK(sec), CFQ_MHASH_SHIFT) -#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) -#define list_entry_hash(ptr) hlist_entry((ptr), struct cfq_rq, hash) - #define list_entry_cfqq(ptr) list_entry((ptr), struct cfq_queue, cfq_list) #define list_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) @@ -112,11 +102,6 @@ struct cfq_data { */ struct hlist_head *cfq_hash; - /* - * global crq hash for all queues - */ - struct hlist_head *crq_hash; - mempool_t *crq_pool; int rq_in_driver; @@ -203,7 +188,6 @@ struct cfq_rq { struct rb_node rb_node; sector_t rb_key; struct request *request; - struct hlist_node hash; struct cfq_queue *cfq_queue; struct cfq_io_context *io_context; @@ -272,42 +256,6 @@ static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *); static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, gfp_t gfp_mask); /* - * lots of deadline iosched dupes, can be abstracted later... - */ -static inline void cfq_del_crq_hash(struct cfq_rq *crq) -{ - hlist_del_init(&crq->hash); -} - -static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq) -{ - const int hash_idx = CFQ_MHASH_FN(rq_hash_key(crq->request)); - - hlist_add_head(&crq->hash, &cfqd->crq_hash[hash_idx]); -} - -static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset) -{ - struct hlist_head *hash_list = &cfqd->crq_hash[CFQ_MHASH_FN(offset)]; - struct hlist_node *entry, *next; - - hlist_for_each_safe(entry, next, hash_list) { - struct cfq_rq *crq = list_entry_hash(entry); - struct request *__rq = crq->request; - - if (!rq_mergeable(__rq)) { - cfq_del_crq_hash(crq); - continue; - } - - if (rq_hash_key(__rq) == offset) - return __rq; - } - - return NULL; -} - -/* * scheduler run of queue, if there are requests pending and no one in the * driver that will restart queueing */ @@ -677,7 +625,6 @@ static void cfq_remove_request(struct request *rq) list_del_init(&rq->queuelist); cfq_del_crq_rb(crq); - cfq_del_crq_hash(crq); } static int @@ -685,34 +632,20 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio) { struct cfq_data *cfqd = q->elevator->elevator_data; struct request *__rq; - int ret; - - __rq = cfq_find_rq_hash(cfqd, bio->bi_sector); - if (__rq && elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_BACK_MERGE; - goto out; - } __rq = cfq_find_rq_fmerge(cfqd, bio); if (__rq && elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_FRONT_MERGE; - goto out; + *req = __rq; + return ELEVATOR_FRONT_MERGE; } return ELEVATOR_NO_MERGE; -out: - *req = __rq; - return ret; } static void cfq_merged_request(request_queue_t *q, struct request *req) { - struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_rq *crq = RQ_DATA(req); - cfq_del_crq_hash(crq); - cfq_add_crq_hash(cfqd, crq); - if (rq_rb_key(req) != crq->rb_key) { struct cfq_queue *cfqq = crq->cfq_queue; @@ -1825,9 +1758,6 @@ static void cfq_insert_request(request_queue_t *q, struct request *rq) list_add_tail(&rq->queuelist, &cfqq->fifo); - if (rq_mergeable(rq)) - cfq_add_crq_hash(cfqd, crq); - cfq_crq_enqueued(cfqd, cfqq, crq); } @@ -2055,7 +1985,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio, RB_CLEAR_NODE(&crq->rb_node); crq->rb_key = 0; crq->request = rq; - INIT_HLIST_NODE(&crq->hash); crq->cfq_queue = cfqq; crq->io_context = cic; @@ -2221,7 +2150,6 @@ static void cfq_exit_queue(elevator_t *e) cfq_shutdown_timer_wq(cfqd); mempool_destroy(cfqd->crq_pool); - kfree(cfqd->crq_hash); kfree(cfqd->cfq_hash); kfree(cfqd); } @@ -2246,20 +2174,14 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e) INIT_LIST_HEAD(&cfqd->empty_list); INIT_LIST_HEAD(&cfqd->cic_list); - cfqd->crq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL); - if (!cfqd->crq_hash) - goto out_crqhash; - cfqd->cfq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL); if (!cfqd->cfq_hash) - goto out_cfqhash; + goto out_crqhash; cfqd->crq_pool = mempool_create_slab_pool(BLKDEV_MIN_RQ, crq_pool); if (!cfqd->crq_pool) goto out_crqpool; - for (i = 0; i < CFQ_MHASH_ENTRIES; i++) - INIT_HLIST_HEAD(&cfqd->crq_hash[i]); for (i = 0; i < CFQ_QHASH_ENTRIES; i++) INIT_HLIST_HEAD(&cfqd->cfq_hash[i]); @@ -2289,8 +2211,6 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e) return cfqd; out_crqpool: kfree(cfqd->cfq_hash); -out_cfqhash: - kfree(cfqd->crq_hash); out_crqhash: kfree(cfqd); return NULL; diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index c7ca9f0..b66e820 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -12,7 +12,6 @@ #include <linux/slab.h> #include <linux/init.h> #include <linux/compiler.h> -#include <linux/hash.h> #include <linux/rbtree.h> /* @@ -24,13 +23,6 @@ static const int writes_starved = 2; /* max times reads can starve a write */ static const int fifo_batch = 16; /* # of sequential requests treated as one by the above parameters. For throughput. */ -static const int deadline_hash_shift = 5; -#define DL_HASH_BLOCK(sec) ((sec) >> 3) -#define DL_HASH_FN(sec) (hash_long(DL_HASH_BLOCK((sec)), deadline_hash_shift)) -#define DL_HASH_ENTRIES (1 << deadline_hash_shift) -#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) -#define ON_HASH(drq) (!hlist_unhashed(&(drq)->hash)) - struct deadline_data { /* * run time data @@ -46,7 +38,6 @@ struct deadline_data { * next in sort order. read, write or both are NULL */ struct deadline_rq *next_drq[2]; - struct hlist_head *hash; /* request hash */ unsigned int batching; /* number of sequential requests made */ sector_t last_sector; /* head position */ unsigned int starved; /* times reads have starved writes */ @@ -75,11 +66,6 @@ struct deadline_rq { struct request *request; /* - * request hash, key is the ending offset (for back merge lookup) - */ - struct hlist_node hash; - - /* * expire fifo */ struct list_head fifo; @@ -93,69 +79,6 @@ static kmem_cache_t *drq_pool; #define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private) /* - * the back merge hash support functions - */ -static inline void __deadline_del_drq_hash(struct deadline_rq *drq) -{ - hlist_del_init(&drq->hash); -} - -static inline void deadline_del_drq_hash(struct deadline_rq *drq) -{ - if (ON_HASH(drq)) - __deadline_del_drq_hash(drq); -} - -static inline void -deadline_add_drq_hash(struct deadline_data *dd, struct deadline_rq *drq) -{ - struct request *rq = drq->request; - - BUG_ON(ON_HASH(drq)); - - hlist_add_head(&drq->hash, &dd->hash[DL_HASH_FN(rq_hash_key(rq))]); -} - -/* - * move hot entry to front of chain - */ -static inline void -deadline_hot_drq_hash(struct deadline_data *dd, struct deadline_rq *drq) -{ - struct request *rq = drq->request; - struct hlist_head *head = &dd->hash[DL_HASH_FN(rq_hash_key(rq))]; - - if (ON_HASH(drq) && &drq->hash != head->first) { - hlist_del(&drq->hash); - hlist_add_head(&drq->hash, head); - } -} - -static struct request * -deadline_find_drq_hash(struct deadline_data *dd, sector_t offset) -{ - struct hlist_head *hash_list = &dd->hash[DL_HASH_FN(offset)]; - struct hlist_node *entry, *next; - struct deadline_rq *drq; - - hlist_for_each_entry_safe(drq, entry, next, hash_list, hash) { - struct request *__rq = drq->request; - - BUG_ON(!ON_HASH(drq)); - - if (!rq_mergeable(__rq)) { - __deadline_del_drq_hash(drq); - continue; - } - - if (rq_hash_key(__rq) == offset) - return __rq; - } - - return NULL; -} - -/* * rb tree support functions */ #define rb_entry_drq(node) rb_entry((node), struct deadline_rq, rb_node) @@ -267,22 +190,19 @@ deadline_add_request(struct request_queue *q, struct request *rq) { struct deadline_data *dd = q->elevator->elevator_data; struct deadline_rq *drq = RQ_DATA(rq); - const int data_dir = rq_data_dir(drq->request); deadline_add_drq_rb(dd, drq); + /* * set expire time (only used for reads) and add to fifo list */ drq->expires = jiffies + dd->fifo_expire[data_dir]; list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]); - - if (rq_mergeable(rq)) - deadline_add_drq_hash(dd, drq); } /* - * remove rq from rbtree, fifo, and hash + * remove rq from rbtree and fifo. */ static void deadline_remove_request(request_queue_t *q, struct request *rq) { @@ -291,7 +211,6 @@ static void deadline_remove_request(request_queue_t *q, struct request *rq) list_del_init(&drq->fifo); deadline_del_drq_rb(dd, drq); - deadline_del_drq_hash(drq); } static int @@ -302,19 +221,6 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) int ret; /* - * see if the merge hash can satisfy a back merge - */ - __rq = deadline_find_drq_hash(dd, bio->bi_sector); - if (__rq) { - BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector); - - if (elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_BACK_MERGE; - goto out; - } - } - - /* * check for front merge */ if (dd->front_merges) { @@ -333,8 +239,6 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) return ELEVATOR_NO_MERGE; out: - if (ret) - deadline_hot_drq_hash(dd, RQ_DATA(__rq)); *req = __rq; return ret; } @@ -345,12 +249,6 @@ static void deadline_merged_request(request_queue_t *q, struct request *req) struct deadline_rq *drq = RQ_DATA(req); /* - * hash always needs to be repositioned, key is end sector - */ - deadline_del_drq_hash(drq); - deadline_add_drq_hash(dd, drq); - - /* * if the merge was a front merge, we need to reposition request */ if (rq_rb_key(req) != drq->rb_key) { @@ -370,13 +268,6 @@ deadline_merged_requests(request_queue_t *q, struct request *req, BUG_ON(!drq); BUG_ON(!dnext); - /* - * reposition drq (this is the merged request) in hash, and in rbtree - * in case of a front merge - */ - deadline_del_drq_hash(drq); - deadline_add_drq_hash(dd, drq); - if (rq_rb_key(req) != drq->rb_key) { deadline_del_drq_rb(dd, drq); deadline_add_drq_rb(dd, drq); @@ -594,7 +485,6 @@ static void deadline_exit_queue(elevator_t *e) BUG_ON(!list_empty(&dd->fifo_list[WRITE])); mempool_destroy(dd->drq_pool); - kfree(dd->hash); kfree(dd); } @@ -605,7 +495,6 @@ static void deadline_exit_queue(elevator_t *e) static void *deadline_init_queue(request_queue_t *q, elevator_t *e) { struct deadline_data *dd; - int i; if (!drq_pool) return NULL; @@ -615,24 +504,13 @@ static void *deadline_init_queue(request_queue_t *q, elevator_t *e) return NULL; memset(dd, 0, sizeof(*dd)); - dd->hash = kmalloc_node(sizeof(struct hlist_head)*DL_HASH_ENTRIES, - GFP_KERNEL, q->node); - if (!dd->hash) { - kfree(dd); - return NULL; - } - dd->drq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, drq_pool, q->node); if (!dd->drq_pool) { - kfree(dd->hash); kfree(dd); return NULL; } - for (i = 0; i < DL_HASH_ENTRIES; i++) - INIT_HLIST_HEAD(&dd->hash[i]); - INIT_LIST_HEAD(&dd->fifo_list[READ]); INIT_LIST_HEAD(&dd->fifo_list[WRITE]); dd->sort_list[READ] = RB_ROOT; @@ -667,8 +545,6 @@ deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio, RB_CLEAR_NODE(&drq->rb_node); drq->request = rq; - INIT_HLIST_NODE(&drq->hash); - INIT_LIST_HEAD(&drq->fifo); rq->elevator_private = drq; diff --git a/block/elevator.c b/block/elevator.c index 4ac97b6..cff1102 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -33,6 +33,7 @@ #include <linux/compiler.h> #include <linux/delay.h> #include <linux/blktrace_api.h> +#include <linux/hash.h> #include <asm/uaccess.h> @@ -40,6 +41,16 @@ static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); /* + * Merge hash stuff. + */ +static const int elv_hash_shift = 6; +#define ELV_HASH_BLOCK(sec) ((sec) >> 3) +#define ELV_HASH_FN(sec) (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift)) +#define ELV_HASH_ENTRIES (1 << elv_hash_shift) +#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) +#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) + +/* * can we safely merge with this request? */ inline int elv_rq_merge_ok(struct request *rq, struct bio *bio) @@ -153,25 +164,41 @@ static struct kobj_type elv_ktype; static elevator_t *elevator_alloc(struct elevator_type *e) { - elevator_t *eq = kmalloc(sizeof(elevator_t), GFP_KERNEL); - if (eq) { - memset(eq, 0, sizeof(*eq)); - eq->ops = &e->ops; - eq->elevator_type = e; - kobject_init(&eq->kobj); - snprintf(eq->kobj.name, KOBJ_NAME_LEN, "%s", "iosched"); - eq->kobj.ktype = &elv_ktype; - mutex_init(&eq->sysfs_lock); - } else { - elevator_put(e); - } + elevator_t *eq; + int i; + + eq = kmalloc(sizeof(elevator_t), GFP_KERNEL); + if (unlikely(!eq)) + goto err; + + memset(eq, 0, sizeof(*eq)); + eq->ops = &e->ops; + eq->elevator_type = e; + kobject_init(&eq->kobj); + snprintf(eq->kobj.name, KOBJ_NAME_LEN, "%s", "iosched"); + eq->kobj.ktype = &elv_ktype; + mutex_init(&eq->sysfs_lock); + + eq->hash = kmalloc(sizeof(struct hlist_head) * ELV_HASH_ENTRIES, GFP_KERNEL); + if (!eq->hash) + goto err; + + for (i = 0; i < ELV_HASH_ENTRIES; i++) + INIT_HLIST_HEAD(&eq->hash[i]); + return eq; +err: + kfree(eq); + elevator_put(e); + return NULL; } static void elevator_release(struct kobject *kobj) { elevator_t *e = container_of(kobj, elevator_t, kobj); + elevator_put(e->elevator_type); + kfree(e->hash); kfree(e); } @@ -223,6 +250,53 @@ void elevator_exit(elevator_t *e) kobject_put(&e->kobj); } +static inline void __elv_rqhash_del(struct request *rq) +{ + hlist_del_init(&rq->hash); +} + +static void elv_rqhash_del(request_queue_t *q, struct request *rq) +{ + if (ELV_ON_HASH(rq)) + __elv_rqhash_del(rq); +} + +static void elv_rqhash_add(request_queue_t *q, struct request *rq) +{ + elevator_t *e = q->elevator; + + BUG_ON(ELV_ON_HASH(rq)); + hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]); +} + +static void elv_rqhash_reposition(request_queue_t *q, struct request *rq) +{ + __elv_rqhash_del(rq); + elv_rqhash_add(q, rq); +} + +static struct request *elv_rqhash_find(request_queue_t *q, sector_t offset) +{ + elevator_t *e = q->elevator; + struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)]; + struct hlist_node *entry, *next; + struct request *rq; + + hlist_for_each_entry_safe(rq, entry, next, hash_list, hash) { + BUG_ON(!ELV_ON_HASH(rq)); + + if (unlikely(!rq_mergeable(rq))) { + __elv_rqhash_del(rq); + continue; + } + + if (rq_hash_key(rq) == offset) + return rq; + } + + return NULL; +} + /* * Insert rq into dispatch queue of q. Queue lock must be held on * entry. If sort != 0, rq is sort-inserted; otherwise, rq will be @@ -235,6 +309,9 @@ void elv_dispatch_sort(request_queue_t *q, struct request *rq) if (q->last_merge == rq) q->last_merge = NULL; + + elv_rqhash_del(q, rq); + q->nr_sorted--; boundary = q->end_sector; @@ -258,11 +335,32 @@ void elv_dispatch_sort(request_queue_t *q, struct request *rq) list_add(&rq->queuelist, entry); } +/* + * This should be in elevator.h, but that requires pulling in rq and q + */ +void elv_dispatch_add_tail(struct request_queue *q, struct request *rq) +{ + if (q->last_merge == rq) + q->last_merge = NULL; + + elv_rqhash_del(q, rq); + + q->nr_sorted--; + + q->end_sector = rq_end_sector(rq); + q->boundary_rq = rq; + list_add_tail(&rq->queuelist, &q->queue_head); +} + int elv_merge(request_queue_t *q, struct request **req, struct bio *bio) { elevator_t *e = q->elevator; + struct request *__rq; int ret; + /* + * First try one-hit cache. + */ if (q->last_merge) { ret = elv_try_merge(q->last_merge, bio); if (ret != ELEVATOR_NO_MERGE) { @@ -271,6 +369,15 @@ int elv_merge(request_queue_t *q, struct request **req, struct bio *bio) } } + /* + * See if our hash lookup can find a potential backmerge. + */ + __rq = elv_rqhash_find(q, bio->bi_sector); + if (__rq && elv_rq_merge_ok(__rq, bio)) { + *req = __rq; + return ELEVATOR_BACK_MERGE; + } + if (e->ops->elevator_merge_fn) return e->ops->elevator_merge_fn(q, req, bio); @@ -284,6 +391,8 @@ void elv_merged_request(request_queue_t *q, struct request *rq) if (e->ops->elevator_merged_fn) e->ops->elevator_merged_fn(q, rq); + elv_rqhash_reposition(q, rq); + q->last_merge = rq; } @@ -294,8 +403,11 @@ void elv_merge_requests(request_queue_t *q, struct request *rq, if (e->ops->elevator_merge_req_fn) e->ops->elevator_merge_req_fn(q, rq, next); - q->nr_sorted--; + elv_rqhash_reposition(q, rq); + elv_rqhash_del(q, next); + + q->nr_sorted--; q->last_merge = rq; } @@ -371,8 +483,12 @@ void elv_insert(request_queue_t *q, struct request *rq, int where) BUG_ON(!blk_fs_request(rq)); rq->cmd_flags |= REQ_SORTED; q->nr_sorted++; - if (q->last_merge == NULL && rq_mergeable(rq)) - q->last_merge = rq; + if (rq_mergeable(rq)) { + elv_rqhash_add(q, rq); + if (!q->last_merge) + q->last_merge = rq; + } + /* * Some ioscheds (cfq) run q->request_fn directly, so * rq cannot be accessed after calling @@ -557,6 +673,7 @@ struct request *elv_next_request(request_queue_t *q) void elv_dequeue_request(request_queue_t *q, struct request *rq) { BUG_ON(list_empty(&rq->queuelist)); + BUG_ON(ELV_ON_HASH(rq)); list_del_init(&rq->queuelist); diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 9b91bb7..9cbf7b5 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -281,6 +281,7 @@ static inline void rq_init(request_queue_t *q, struct request *rq) { INIT_LIST_HEAD(&rq->queuelist); INIT_LIST_HEAD(&rq->donelist); + INIT_HLIST_NODE(&rq->hash); rq->errors = 0; rq->rq_status = RQ_ACTIVE; @@ -2700,6 +2701,7 @@ void __blk_put_request(request_queue_t *q, struct request *req) int priv = req->cmd_flags & REQ_ELVPRIV; BUG_ON(!list_empty(&req->queuelist)); + BUG_ON(!hlist_unhashed(&req->hash)); blk_free_request(q, req); freed_request(q, rw, priv); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b2a412c..8f54869 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -229,6 +229,8 @@ struct request { struct bio *bio; struct bio *biotail; + struct hlist_node hash; /* merge hash */ + void *elevator_private; void *completion_data; @@ -697,21 +699,6 @@ static inline void blkdev_dequeue_request(struct request *req) } /* - * This should be in elevator.h, but that requires pulling in rq and q - */ -static inline void elv_dispatch_add_tail(struct request_queue *q, - struct request *rq) -{ - if (q->last_merge == rq) - q->last_merge = NULL; - q->nr_sorted--; - - q->end_sector = rq_end_sector(rq); - q->boundary_rq = rq; - list_add_tail(&rq->queuelist, &q->queue_head); -} - -/* * Access functions for manipulating queue properties */ extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 1713ace..2c270e9 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -82,12 +82,14 @@ struct elevator_queue struct kobject kobj; struct elevator_type *elevator_type; struct mutex sysfs_lock; + struct hlist_head *hash; }; /* * block elevator interface */ extern void elv_dispatch_sort(request_queue_t *, struct request *); +extern void elv_dispatch_add_tail(request_queue_t *, struct request *); extern void elv_add_request(request_queue_t *, struct request *, int, int); extern void __elv_add_request(request_queue_t *, struct request *, int, int); extern void elv_insert(request_queue_t *, struct request *, int); |
